Bacterial incubator.



J. BOEKEL SI1. H. SCHERER.

BACTERIAL INCUBATOR. APPLICATION FILED ocT.'20. 1914.

I Patented uly 6, 1915.

K 2 SHE TS-TSHEET 2.

entran sraaras Parana cranica JULIUS BOEKEL ANDKJOHN H. SCHERER, 0F PHILADELPHIA, PENNSYLVANIA,

` ASSIGNORS TO SAID BOEKEL.

BACTERIAL INCUBA'IOR.

Application led October 20, 1914.

To all 'whom it may concern.'

Be it known that we, JULIUS BoEKEL and JOHN H. SCHERER, citizens of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Bacterial Incubators, of which the following is a specification.

The object of this invention is to provide certain and automatic means for maintaining the temperature needed in the incubation of bacteria and especially for preventing the temperature from rising above the degree best suited to any particularculture or species. To this end we make use of heating means for the automatic circulation of air in contact with means of refrigeration and control the same automatically by a thermostat adjusted to the proper degree and arranged in the incubating chamber,-

through which the current of air l'ows in its circuit.

I rThe invention consists mainly in the said combination of devices, which mayalso be used for other purposes than propagation of bacteria.

It also consists in some ancillary and subsidiary-devices and in the special construction and'combination of the parts hereinafter more particularly set forth and claimed.

1n the accompanying drawings: Figure 1 represents a front elevation of a bacterial incubator embodying our invention; Fig. 2,

a vertical centraLsection from front to rear of the same, Fig. 3, an enlarged detail view in` vertical section of the drip tube and valve; Fig. 4f, a transverse sectlonal view of the same looking in the direction of the arrows Fig. '2; and Fig. 5, a diagrammatic view of the circuit, showing the heater in section.

The casing 1 of the body of our incubator has an exterior wall of asbestos protected at the corners and edges by sheet metal sheathing 2 and a. packing Biot' cork between theexterior asbestos wall and the sheet metal inner wall 4. This casing rests upon a stout metallic drip pan 5, which tits into the top of a supporting base 6 having legs 7. -A drip pipe 8, having an outlet resilient metal Specification of Letters Patent.

Patented Juiy 6, i915.

serial No. 867,594.

terior otl said incubator body. rthus the wa ter from the melted ice and the water of condensation will escape into the drip pan at the same time. A vertical depending partition l2 extends from the bottom of said ice box down parallel and proximate to said pipe, forming -a vertical passa-ge 13 between said partition and the nearer side wall of the incubator casing. This partition ends some distance above the floor of the interior of the incubator chamber. At the opposite side of said ice box the latter is provided with ay vertical raised wall 14 forming a similar passage 15 on that side and similarly stopping short of the top of the interior otl said incubator body. The space next below said ice box and between said depending partition l2 and the side ot' the casing `1norere1note therefrom and below passage 15 constitutes an incubating chamber 16 containing shelves 17 for supporting trays or other receptacles for bacterial cultures exposed to incubation.

Divers bacteria will not develop except at. a relatively low temperature, for example, less than forty degrees: and of those kinds some require lower degrees than others, and also any appreciable variation either way from the determined temperature will injure the bacteria. It therefore becomes necessary for a steady temperature in the incubating chamber of less than will ordinarily be found in the atmospheric air and to regulate this conveniently and automatically` insuring steady and equal conditions in all parts of said incubating chamber. This is accomplished by providing a circulation of air through the ice box. down passage 13. then through thc incubating chamber and'up passage 15 to the ice box again. Such a current might obviously be created by supplemental mechanical devices -controlled by hand; but it is obviously advisable V1 oo within said chamber and connections which normally make circuit through said thermostat and heater and thus put said heating device into action so as tocreate a current through the ice box as described. Of course this' heating device must not heat the incubator chamber suiiiciently to counteract in any appreciable degree this cooling action. For such uses electric devices are best. lVe have therefore shown an electric heater 18 attached to the underside of the lowest shelf 17 of the incubating chamber and a thermostat 19 attached to the inner Wall of the incubating chamber just under the upper shelf thereof.

rl`hc thermostat and heater may be of any suitable or convenient type, as we claim no novelty `in their construction and the forms shown are for illustration only. It is esscntial however that they be capable of very delicate adjustment and of quick response to the most minute change in temperature. Electric conducting wires 20 extend from this thermostat 19, and connect the heater 18 therewith to be controlled thereby. Therefore, when the temperature in the incubating chamber rises above a predetermined point it causes the thermostat to open the circuit and thereby disconnect the heater until the incubating chamber and thermostat have so far cooled oit that the latter will again close the circuit and thereby once more bring the heater into operation. The

degree of temperature at which such action takes place will of course depend on the adjustment of the thermostat, which has an adjusting 'screw .Q1 extending through the side of the casing and an external switchboard or frame 22 on which an electric lamp 23 Aand a hand-operated switch or circuit closerv 24 are also mounted, bothlbeing insaid electric circuit. This lamp of course shows whether the circuit be closed or open and this switch makes it practicable to open or close the circuit by hand whenever desired.

The ice-box has an opening at the top and a removable cover 25 therefor, forming part of thc incubator casing and has at the. front and rear interior face of its bottom two strips Q6 and 2 respectively for supporting the ice slightly clear of the bottom, thus providing an easy'drain of water, the strip 27 also being formed so as to direct the water to the top of the drain. The incubator chamber is provided with hinged doors 28 and 29, forming an insulating dead air space between them, for ,the admission and withdrawal of cultures and receptacles. kThese doors form part of the front of said casing. The shelves of the latter rest preferably on brackets 30 fastened to the inner walls of the incubator casing. These details may of course be varied and other means of refrigeration may be substituted for ice, many l. An incubator casing and a refrigerating chamber and incubating chamber' in said casing, a heater within said casing arranged to cause a current of air through said chambers, a thermostat in said incubating chamber and electrical connections between said thermostat and heater whereby said thermostat automatically controls the action of said heaterl and the temperature of the inicubating chamber. I

2. In combination with the hollow body of an incubator, partitions therein forming 'an ice-box in its upper part and an incubating chamber below said ice-box, and also leaving passages at the sides of these parts for thecirculation of air through said charnbers, an electric heater arranged undersaidv incubating chamber, a thermostat arranged in the latter and connections whereby the said thermostat will open the circuit through said heater when the temperature of said incubating chamber rises above acertain degree.

3. Means for regulating temperature comprising a thermostat, electric circuit connections, a heater governed thereby, means of refrigeration and an inclosing casing provided with devices arranged to form passagcs'for the circulation in contact with said refrigerating means and said thermostat ofV the air set in circulation by said heater, the

said heater, refrigerating means and thermostat being in proximity to each other and operating to maintain automatically a predetermined moderate degree of temperature within said casing.

4. In combination with an incubator, icebox and heater contained therein, Which are arranged tomaintain circulation of air through said ice-box and the remainder of the interior of said incubator, a thermostat in said incubator, electric connections from said thermostat to said heater and means external to said incubator for adjusting the said. thermostat to regulate the degree of heat at which it will operate.

5. In combination with an incubator, an ice-box and an electric heater contained therein andarranged to maintain a circulation of air through said' ice-box and the remander of the interior of said incubator, a name to this specification in the presence of thermostat Within said'ineuba'tor and co two subscribing Witnesses. nections therefrom for energizing said JULIUS BOEKEL. heater, and a hand operated switch insaid JOHN H. SCHEi-tint. 5 circuit, which is accessible from the exterior Witnesses: y

of said incubator. FREDK. MANGOLD, n testimony whereof, I have signed my ROBERT J. HAMILTGN. 

